A liquid crystal display (LCD) controls light transmittance of liquid crystal in accordance with an image signal to display an image. An LCD may include an LCD panel, a driving circuit unit and a back light unit. LCDs may be used as a display device such as a notebook computer, a computer monitor and various home appliances such as televisions. In an LCD panel, a thin film transistor array and a color filter substrate are separated from each other at uniform intervals, liquid crystal is implanted between the thin film transistor array and the color filter substrate, and polarizing plates are attached to both sides of the panel. A multi-channel output LCD drive integrated circuit (LDI) is used as the signal wiring line of the LCD panel so that a signal can be easily supplied.
As illustrated in example FIG. 1, a plurality of LDI chips 100 are formed on and/or over LCD panel 102 and are in charge of various parts of a screen. Some LDI chips may be used in the panel. LDI chip 100 has an R-string structure in which a plurality of resistors are connected, a power source voltage is reduced by the plurality of resistors, and a voltage corresponding to the bit value of digital image information is selected to be applied to a pixel.
As illustrated in example FIG. 2, in the R-string structure, the area of silicide formed on and/or over a poly pattern 200 is controlled by the size of silicide-anti blocking area (hereinafter, referred to as SAB) pattern 202 in wide poly pattern 200 so that resistance and an output voltage are controlled. However, in a patterning process, a change in the critical dimension (CD) of a pattern may occur in an exposure process, which results in changing the value of the resistance. For example, if the CD of SAB pattern 202 formed in an upper portion becomes smaller than the CD of SAB pattern 202 formed in a lower portion in the course of the exposure process, an un-silicide poly area that occupies most of the resistance is reduced so that the resistance is reduced. Therefore, the magnitudes of resistance are different from each other in the LDI chips where the sizes of SAB patterns are different from each other. As a result, a difference in an output voltage is generated in the R-string structure so that the operation characteristics of the LDI chips are different from each other.